Metal roof structures typically comprise a series of parallel rafter beams extending across the building in one direction and purlin beams parallel to each other mounted on top of the rafters extending in a direction normal to the rafters. Insulation material in long sheets is placed in the area between purlins. The sheets of insulation material can be laid along the length of the purlins or across the purlins in a direction normal to the purlins. If desired, the roof structure can have a first layer of insulation material which is laid along the length of the purlins, and a second layer of insulation material which is laid laterally across the purlins on top of the first layer on insulation. Hard roofing material such as metal decking is then attached on top of the purlins over the insulation material. Because the hard roofing material comes in long sheets and the roofs generally have two sloped sections, it is customary to construct the roof along the length of the structure from one end to the other. The workers stand on the previously laid section of roof to construct the next section.
The insulation material must be supported between the purlins beneath the hard roofing material. Various methods of supporting the insulation material have been used. Mounting straps or wire mesh which are attached to or draped over the purlins forming a lattice have been used. This is referred to as banding. A sheet, typically made of vinyl and acting as a vapor barrier, is then rolled onto the lattice, and insulation material is placed between adjacent purlins and over the sheet. If the installation of the lattice is done from underneath the roof structure, scaffolding or lifting equipment is typically required for installation. Since the lattice encompasses the entire roof, installation is costly and time consuming. Once the hard roofing material is mounted on the purlins, the sheet can support the insulation material and the lattice no longer serves any useful purpose.
Some systems dispense with the lattice and use the sheet itself to support the insulation material. The support sheet is draped from the adjacent purlins and the insulation material is placed on top of the support sheet. A carriage has been used to aid in the dispensing of the support sheet. The carriage is positioned on top of the purlins and travels the length of the purlins during the roof construction. A roll of the support sheet material is mounted on the carriage and the support sheet is payed out from the roll and placed on top of the purlins. As the carriage travels the length of the purlins, the support sheet is draped across the purlins.
Insulation material which is laid along the length of the purlins on top of the support sheet is typically dispensed from a roll. After each movement of the carriage, the workers push each individual roll of insulation material a sufficient distance so that the next sheet of hard roofing material can be fastened to the purlins. Typically, the workers push each roll of insulation material by kicking the rolls in the direction of carriage movement. Although this system of pushing each roll of insulation material has been found to be adequate, it is inconvenient and time consuming to push each roll, after every relatively small carriage movement.
An alternative to manually unrolling the roll of insulation is to mount the roll of insulation material on a mandrel so the insulation material can be payed out as the carriage moves along the roof. The mandrel is typically an elongated rod which is placed through the center of the roll of insulation material. The mandrel is rotatably fastened to a framework or cradle which is mounted on the carriage, thereby supporting the roll of insulation material axially. As the carriage moves along the length of the purlins, the insulation is payed out from the rotating roll. This system eliminates the need for the workers to separately push each roll of insulation material as the carriage is periodically moved. However, after a roll is completely dispensed, a new roll has to be inserted on the mandrel and then placed on the framework. Since a typical roll of insulation material is relatively short compared to the length of the roof, a new roll will frequently have to be inserted. For example, a roll of insulation material having a desired recovery thickness of about 6 to 8 inches (15 to 20 cm) is only about 25 to about 30 feet (9.1 to 10.9 m) long. This system is, likewise, time consuming and inconvenient.
It would be desirable to have an apparatus for assisting in the building of a roof structure which is efficient and convenient to use.